Adjustable and yieldable male bending die



Sept. 18, 1951 v. WILDMAN ADJUSTABLE- AND YIELDABLE MALE BENDING DIE 2 Sheets-Sheet 1 Filed March 11, 1948 Willi INVENTOR. VE'IENE W/LDMAN A 7' OENEYS Z'Shgets-Shget 2 IN VEN TOR. V'EA/E W /l DMA/V -/4 TTOFE/VEYS 5 WW. v

Sept. 18, 1951 v. WILDMAN ADJUSTABLE AND YIELDABLE MALE BENDING DIE Filed March 11, 1948 Patented Sept. 18, 1951 ADJUSTABLE AND YlELDABLE ,MALE

' N DI Verne Wildman, Warren, hio',"assignor to The American-:Welding;& ManufacturingiCompany, -Warrcn, :Ohio,-; a: corporation f Ohio- 'ApplicationMarch 11, 1948, Serial No. 14,237

The present invention relates generally to metalshaping and forming dies and ismore'particul-arly concerned with a novel and very useful male *die for-bending metal angle stock without wrinkling or buckling said stock.

- whena' length of angle stockis bent in accordance with conventional practice, the final article is usuall wrinkled in the vicinity of each 'bend for lack of i'the' application of a positive-shaping er -retaining force upon the sides of'the stock while adjacentportions arebeing bent. In efforts to-overcome this'difficulty others have devised die-means intended to preserve the-flange shape as' bending is accomplished, but such means have been. of'limited utility and value due to the fact that-a given die of this type can be used -only with stock of oneparticular flangethickness; To overcome this difilculty these devices may be provided withadjustment -means,-but would then require special attentionsinvolving careful measurement with each variation of stock thickness,

and wouldthusbe uneconomical and-impractical. In accordancewith the present invention, these variousshortcomings of the prior art can be overcome easily and economically through a novel combination of relatively few uncomplicatedel'ements which do not require'high precisionwork in their manufacture and assembly, but are nevertheless fully effective in preventing the-wrinkling of stockin metal bending operations. Moreover, the present device is automatically-adaptable to variations in stock thickness since-itmay expand and contract resiliently, dc"- pending upon the thickness of various portions of the stock to which it is applied. In other words, because of its design and the principles upon which its operation is based, the present device inherently is much more adaptablethan any heretofore known analogous device. In addi tion, my die is easily and quickly assembled and disassembled without special skill or care,and can be used for long periods without either ad'- justment or maintenance attentions. V

A more thorough understanding of my present invention and a further realization of the advantages which it possesses will be gained'by those skilled in the art from the following detailed-description of this invention in apreferred form, illustrated in the drawings-accompanying and-*forming 7 part of this specification, in which,

,2 0 v Figure I is a side elevational view, partly in section and with parts broken away, of an anglestockbending die assembly including a male 'die embodying" this invention, and-showing a length of stock in positionjust prior to bending; Figure 2 is a View similar to that of Fig. 1, showing the female die in-its'extreme advanced position at the end of the stockebending-oper ation;

"Figure 3-is a front end elevational viewof'the Fig. 1 assembly with a portion of the male die broken awayto show its internal construction; Figure'A is a side elevational view, partly'in section, of the male die of Fig. 1, showing its internal-construction; FigureS -is' a reduced scale view of the angle segment; shown in Fig. 1, illustrating the final shape'of'i'the'isegment after its release from-the die-assembly; and,

Fig. 6 is" a fragmentary, end elevational view of theiEig. I assembly with'a'portion broken away in thei interest of clarity. .Theillustrated male die of my" invention comprisesa pair of side plates in and a middle plate 1 laall of which are of the same general shape and dimensions" and provided with three registered tran'sversefiapertures' through which extend three bolts:- lliccarrying. nuts l5-and limiting movement offplate ll outwardrelative to plate ll. Plates I ll have edge surfaces [1' and side surfaces l8 at'tright angles thereto to engage substantially the:entire*inner surface of an angle stock seg ment' S just prior to and during the bending operation", andthe end portions of these edges, as viewed in Fig; hare-straight and define an included angle of about 85, while the mid-portions 2|. arearcuate and define the curvature to bepr'oduced. in stock. S. Plate H has an edge 2245f similar contour disposed alongside of the said side plate edges, and further is provided with"a..pluraltiy of transverseapertures 23 most of which are adjacent to edge 22 and'in all of which'compression springs 25 are disposed, extendingbetween and at all times firmly and res il iently' bearing against opposing inside surfaces ofthe side plates. The middle plate also has two laterally extending apertures 26 and 21 through which two bolts 29 and 30 extend with their threa'dd en'ds being screwed into aligned threaded holes in a carryingbracket-M whereby 3 the die is secured to a die holder or machine (not shown) suitably of conventional construction and having means for moving the die vertically to engage or disengage stock S.

Referring to Figs. 1 and 2, the female die of the illustrated assembly comprises a fixed shoe 35 and a sliding shoe 36, both of which, however, are of substantially the same effective dimensions and configuration. In end view each of these shoes has an inner generally U-shaped working surface to engage substantially the entire outer surface portions of both segments of stock S during the bending operation. Fixed shoe 35 is carried by a conventional die holder or machine indicated at H, while shoe 36 is supported by a pivotally mounted bracket 39 having a portion 40 extending under and engaging,

the bottom of the shoe 36 and having a pair of spaced apart parallel arms 4| disposed on opposite sides of the male die. Arms 4| are transversely apertured near their free ends to receive shafts 43 which are on the center of curvature of edge portions 2| and are rotatably carried by the aforementioned die holder whereby the bracket 39 and sliding shoe 36 are maintained in relative position with respect to edge surfaces ll. Thus shoe 36 in the bending operation is moved outwardly and upwardly around shafts 43 as pivots, from the position shown in Fig.1 to that shown in Fig. 2, with bracket 39 sliding over shoe 36, the force causing this movement being provided by means including a rod 45 pivotally attached to an apertured lug 46 carried by bracket 39 and operatively engaged with means (not shown) such as a piston actuated by pneumatic pressure.

As will be clear from the drawings, angle stock S is bent by the assembly of Fig. 1 by moving the stock segment into engagement with fixed shoe 35 and sliding shoe 36 and then gripping both segments between the male and female dies as illustrated in Fig. 3. Shoe 36 is then moved, turning the stock around the curved face of edge I! and bending it through slightly more than 90, thus allowing for spring-back, since a. 90

bend is in this case desired. The operation may be repeated any desired number of times, depending upon the length of the stock and the use to which the bent stock is to be put, and the finished bends will uniformly have the perfect contour illustrated in Fig. 5. Due to the firm engagement of the sides of the male and female dies with the flanged portion of the stock at all critical times, there is no possibility of the stock wrinkling during bending.

It will be understood that the number, location and strength of springs will be determined by'the force which is required to prevent wrinkling of the stock during bending. It will be apparent furthermore that resilient means other than springs, such as rubber elements, may satisfactorily be employed in male dies of the pres- What is claimed is:

1. A die for bending metal angle stock which comprises side plates and a middle plate therebetween and spaced from the side plates, said side plates having edge surfaces along which the stock is to be bent and side surfaces to engage and prevent wrinkling of said stock during such bending, means extending through saidplates to limit outward movement of the side plates relative to the middle plate, and resilient means carried by the middle plate and bearing against said side plate and constantly urging said plates outwardly away from said middle plate, said resilient means being disposed between said stock engaging side surfaces of the side plates.

2. A die for bending metal angle stock which comprises side plates and a middle plate therebetween and spaced from the side plates, said side plates having edge surfaces along which the stock is to be bent and side surfaces to engage and prevent wrinkling of said stock during such bending, means extending through said plates to limit outward movement of the side plates relative'to the middle plate, and resilient means including a plurality ofjsprings carried by the middle plate and bearing against said side plates and constantly urging said plates outwardly away from said middle plate, said resilient means being disposed between said stock engaging side surfaces of the sideplates.

. '3. A die for bending metal angle stock which comprises side plates and a middle plate therebetween and spaced from the side plates, said side plates having edge surfaces along which the stock i to be bent and side surfaces to engage and prevent wrinkling of said stock during such bending, and said middle plate having a plurality of transverse apertures, means extending through said plates to limit outward movement of the side plates relative to the middle plate, and resilient means in the apertures of the middle plate and bearing against said side plates and constantly urging said plates outwardly away from said middle plate, said resilient means being disposed between said stock engaging side surfaces of the side plates.

' 4, A die for bending metal angle stock which comprises side plates and a middle plate therebetween and spaced from the side plates, said side plates having edge surfaces along which the stock is to be bent and side surfaces to engage and prevent wrinkling of said stock during such bending, and said middle plate having a plurality of transverse apertures in its edge portion adjacent to the stock-engaging edge surfaces of the side plates, means extending through said plates'to limit outward movement of the side plates relative to the middle plate, and resilient means including a plurality of springs in the apertures of the middle plate and bearing against said side plates in the region of the stock-engaging side surfaces of said plates and constantly urging the side plates outwardly away from said middle plate.

5. A die for bending metal angle stock which comprises side plates and a middle plate therebetween and spaced from the side plates and having a plurality of transverse apertures in register with transverse apertures in the side plates, said side plates having edge surfaces along which the stock is to be bent and side surfaces to engage and prevent wrinkling of said stock duringsuch bending, and said middle plate having, a plurality of transverse apertures, means including bolts extendingthrough the registered apertures of said middle plate and side plates REFERENCES CITED to limit outward movement of the side plates The followin references are of record in the relative to the middle plate, and resilient means file of this patient: carried by the middle plate and bearing against m said side plates and constantly urging said plates UNITED STAJLES PATENTS outwardly away from said middle plate, said Numc'er Name Date resilient means comprising a plurality of springs 137,339 Blakslee Apr. 1, 1873 disposed in said transverse apertures of the 735,307 Smith Aug. 4, 1903 middle plate, said resilient means being disposed 1,360,450 Scott Nov. 30, 1920 between said stock engaging side surfaces of the if! 2,066,360 Nast Jan. 5, 1937 side plates. 1 2,266,912 Shaw Dec. 23, 1941 VERNE WILDMAN. 2,287,933 Green June 30, 1942 2,476,595 Green July 19, 1949 

